1. Field of the Invention
The present invention is in the field of telecommunications, and in particular to the field of management of voice calls in order to minimize call cost while maintaining satisfactory call voice quality.
2. Discussion of the State of the Art
When the contact center industry first arose some forty years ago, there was only one way to deliver voice calls, which is to say via a telephone network to standard telephone endpoints. In fact, forty years ago there was only one long distance provider in the United States, which enjoyed a government-regulated monopoly of long-distance telephony (the situation was generally the same in other countries). Contact centers (often also called call centers, which for purposes of the present application will be considered synonymous with contact centers) began to emerge in the United States as a result of the introduction of toll-free 800 numbers, which made it possible for large enterprises to encourage their customers to call them via a nationwide number that did not incur toll charges and therefore did not cost customers anything. Previously, as long-distance rates were high enough that people thought twice before making a long-distance call, it would have been highly unlikely for a consumer to call a national company, incurring long-distance charges, for anything other than substantial reasons. The growth of contact centers in the ensuing forty years has been nothing short of dramatic, with several million Americans now working in contact centers.
While the call management options available to enterprises forty years ago were extremely limited, the opposite is true today. There are numerous long-distance network operators, each with different strengths and weaknesses. Calls can be delivered not only over traditional telephones, but also using Internet Protocol (IP) telephony systems, and terminal devices can be “regular” phones with “plain old telephony service” (POTS), digital phones with Channel-Associated Signaling (CAS) or Integrated Services Digital Network (ISDN) service, or headsets connected to personal computers or workstations which either have an analog card, digital time division multiplexing (TDM) card or have an IP telephone software installed. Moreover, while in the early days of the industry agents were typically located centrally at a single facility at which a private branch exchange (PBX) with automated call distribution software (ACD) software either installed or operating on a server closely tied to the PBX, today agents are often distributed across several domestic or international call center locations, and many even work from home or small branch offices. Additionally, call switching devices are now sometimes located “in the cloud”, which might be either a telephony carrier's facility, or a facility provided by non-telephony focused third parties, or at one or more centralized data centers. Data centers serving large scale contact centers operated by an enterprise desiring to serve its customers are often sited in order to take advantage of inexpensive electrical power or readily available large scale data networking infrastructure, while call centers are often located in small and medium-sized communities with available labor pools and low labor costs. And third party companies often operate data centers; in fact, it is not at all uncommon to have multiple parties involved in “value chains” that deliver service to consumers. These examples are but samples of the many ways in which contact centers have become more complex since their origins forty years ago.
One constant amidst all of the emerging complexity of large-scale contact centers is the need for quality, as perceived by the customers of an enterprise. While there are several factors that contribute to quality, such as time spent waiting to speak to an agent, attitude of agents, and whether a desired service was indeed received, one aspect that is assumed in developed countries is that the quality of the voice signals used in service situations should be excellent. Consumers do not enjoy being misunderstood because of poor connections, and even more they do not enjoy hearing poor sound quality; when a consumer calls a major bank, she assumes the sound quality will be at least as good as what she grew up with. Clearly, providing high quality audio or voice channels during service calls is a necessary element of high quality service (a newer development that makes this even more important is the fact that, in some cases, even the agents who serve customers are independent of the enterprise, and may have choices as to which enterprises to serve as contractor agents possibly working at home; alienating agents by providing poor voice channel quality is also an important quality factor in these situations). Also, when enterprises carry calls between facilities under their control using their own IP networks, it is important that call quality is maintained in order that expensive knowledge workers are not annoyed or made less productive by poor-quality phone calls and the ensuing communications challenges.
Enterprises clearly desire to enjoy the economic advantages that IP telephony provides, particularly lower cost (because it is less expensive per minute of talk time to carry a call over a general-purpose leased data network rather than a toll call) and increased flexibility (because enterprises can directly control the distribution of calls more easily when they are all carried on a common network backbone under their control). In the art, several approaches have emerged to balance the desire to shift to IP telephony against the need for maintaining call quality. One of these is the management of network quality of service (QoS) generally. Another is the reservation of dedicated bandwidth for high-priority, real-time uses such as carrying telephone calls or videoconferences (typically, large data-centric uses can function well with varying QoS as long as an aggregate minimum bandwidth is maintained, but with real-time uses, even short dips in bandwidth can cause important quality issues). There are many techniques available in the art for monitoring the quality of a given telephone call, including but not limited to R Factor, Mean Opinion Score (MOS), RTCP XR, P.861 (PSQM)/P.862 and monitoring call completion or dropped call rates, any combination of which may be used by enterprises to measure call quality on a call-by-call basis (non-intrusive monitoring) or through the use of active test calls.
However, when agents (in contact center situations) or other employees of an enterprise are located either at home or at small, distributed facilities, often connected to the enterprise's core data and networking systems by infrastructure not under the control of the enterprise (for example, a home agent using a DSL line provided by his phone carrier and connecting to an enterprise via a virtual private network), it is much harder for enterprises to ensure adequate call quality, and in many cases enterprises elect to adopt higher-cost media channels, such as long-distance telephony or ISDN lines, to ensure that problems do not occur. In these cases, it becomes nearly impossible for the enterprise to ensure voice quality; nevertheless, it is still economically desirable to use IP telephony when possible. What is needed is the ability for an enterprise to use IP telephony when quality is good, but to switch seamlessly to TDM (or POTS) when call quality degrades.
Accordingly, it is an object to provide a system and methods for adaptively managing call quality in order to allow maximum use of low-cost channels such as IP telephony while maintaining quality within acceptable boundaries, and to allow for real-time optimization of the combination of quality and cost without losing any calls in progress.